The present invention relates to a semi-buried facility for storing dangerous materials packaged into containers (10), including: at least one cell (2) defined by buried vertical firewalls (3a) forming a pit containing said containers; and each cell being surrounded by a chamber including vertical firewalls (7a) extending above the ground; and at least one container (10) depositing and receiving area (6; 25), such as a roadway (6) for trucks (6a), and/or an area (25) for handling containers (10) from or to a railway transport line (22); and a corridor-shaped depositing area (5) inside each of said chambers between each of said buried cells and a longitudinal chamber wall (7a); and a motor-driven container handling gantry crane (8) capable of moving one of said containers (8c) that has been suspended to a height greater than that of said chamber walls (7a).